package com.xmmxjy.common.util;

/**
 * Created by xmm on 2017/2/9.
 */
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.springframework.objenesis.Objenesis;
import org.springframework.objenesis.ObjenesisStd;

import com.dyuproject.protostuff.LinkedBuffer;
import com.dyuproject.protostuff.ProtobufIOUtil;
import com.dyuproject.protostuff.ProtostuffIOUtil;
import com.dyuproject.protostuff.Schema;
import com.dyuproject.protostuff.runtime.RuntimeSchema;
/**
 * @Description：Protobuff插件序列化
 */
public class ProtobuffSerializationUtil {
    private static Map<Class<?>, Schema<?>> cachedSchema = new ConcurrentHashMap<Class<?>, Schema<?>>();
    private static Objenesis objenesis = new ObjenesisStd(true);

    public static<T> Schema<T> getSchema(Class<T> clazz){
        @SuppressWarnings("unchecked")
        Schema<T> schema = (Schema<T>) cachedSchema.get(clazz);
        if (schema == null) {
            schema = RuntimeSchema.getSchema(clazz);
            if (schema != null) {
                cachedSchema.put(clazz, schema);
            }
        }
        return schema;
    }

    /**
     * 序列化
     *
     * @param obj
     * @return
     */
    public static <T> byte[] serialize(T obj) {
        @SuppressWarnings("unchecked")
        Class<T> clazz = (Class<T>) obj.getClass();
        LinkedBuffer buffer = LinkedBuffer
                .allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE);
        try {
            Schema<T> schema = getSchema(clazz);
            return ProtobufIOUtil.toByteArray(obj, schema, buffer);
        } catch (Exception e) {
            throw new IllegalStateException(e.getMessage(), e);
        } finally {
            buffer.clear();
        }
    }
    /**
     * 序列化List
     *
     * @param obj
     * @return
     */
    public static <T> byte[] serializeList(List<T> objList) {
        if(objList == null || objList.isEmpty()){
            throw new RuntimeException("序列化对象列表("+objList+")参数异常！");
        }
        @SuppressWarnings("unchecked")
        Class<T> clazz = (Class<T>) objList.get(0).getClass();
        LinkedBuffer buffer = LinkedBuffer
                .allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE);
        byte[] protostuff = null;
        ByteArrayOutputStream bos = null;
        try {
            bos = new ByteArrayOutputStream();
            Schema<T> schema = getSchema(clazz);
            ProtostuffIOUtil.writeListTo(bos,objList,schema,buffer);
            protostuff = bos.toByteArray();
            return protostuff;
        } catch (Exception e) {
            throw new IllegalStateException(e.getMessage(), e);
        } finally {
            buffer.clear();
        }
    }
    /**
     * 反序列化
     *
     * @param data
     * @param clazz
     * @return
     */
    public static <T> T deserialize(byte[] data, Class<T> clazz) {
        try {
            T obj = objenesis.newInstance(clazz);
            Schema<T> schema = getSchema(clazz);
            ProtobufIOUtil.mergeFrom(data, obj, schema);
            return obj;
        } catch (Exception e) {
            throw new IllegalStateException(e.getMessage(), e);
        }
    }
    /**
     * 反序列化List
     *
     * @param data
     * @param clazz
     * @return
     */
    public static <T> List<T> deserializeList(byte[] data, Class<T> clazz) {
        if(data == null || data.length == 0){
            throw new RuntimeException("反序列化对象发生异常，byte序列为空！");
        }
        try {
            Schema<T> schema = getSchema(clazz);
            List<T> result = null;
            result = ProtostuffIOUtil.parseListFrom(new ByteArrayInputStream(data),schema);
            return result;
        } catch (Exception e) {
            throw new IllegalStateException(e.getMessage(), e);
        }
    }

}
